Alexander jay wurts



(No Model.) I I .A. J. WURTS.

NON-WELDING CONTACT. No. 550,3 0.

WITNESSES:

, INVENTOH AITTOHIVEYJ Patented Nov. 26,1895."

UNITE STATES ALEXANDER JAY XVURTS, OF

TITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE VVESTINGIIOUSE ELECTRIC AND MANUFACTURING COMPANY, OF

SAME PLACE.

NON-WELDING CONTACT.

SPECIFICATION forming part of Letters Patent NO. 550,360, dated November 26, 1895. Application filed'April 11, 1895. Serial No. 545,282. (No model.)

To all whom it may concern.-

. Be it known that I, ALEXANDER J AY WURTS, a citizen of the United States, residing in Pittsburg in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Non -Welding Contacts and the Method of Making the Same, (Case No. 635,) of which the following is 'a specification.

My invention relates to electrical contact devices, and more particularly to such devices as are employed in connection with relays and similar instruments employed in electrical signaling systems; and it has for its object to provide contacts adapted for use in such relations which will be reliable and operative under all conditions of working.

Relays-such, 'for example, as those employed in connection with electrical signaling systems-contain small contacts so mounted and located as to be brought together and separated quickly by means of slight actuating forces. The separating means, usuallya spring, is so weak that the contacts are liable to stick together, particularly during thunder storms, when the passage of static discharges from one contact to the other forms what might be called a weld. This apparent fusing together of the two metal contactpieces is obviously avery serious defect, since itrenders the instrument entirely inoperative. It is customary to make the tips of the contact-pieces in such devices ofmetal which has a high fusing-point-such, for instance, as platinum; but even when constructed of such material the difliculty above mentioned is not avoided, from which it seems probable that the sticking together of the contacts is not, properly speaking, due to fusion, but is rather a sort of interlocking of the parts, which is independent of temperature;

As a result of experiments entered into with a view to obviating the defects above noted, I have foundthat contact-points constructed of a properly formed amalgam fully meet the requirements under all conditions of working.

In order to secure an amalgam which shall be entirely satisfactory and which shall at all times and under all circumstances preclude the sticking together of the vcontact-points, I find it practicable and desirable to form an amalgam paste by electrolytically depositing the metal employed, preferably copper, into mercury; but I do not claim this particular method as my invention. The fine amalgam paste prepared by this or such other method as may be found suitable I press into a solid plug of the desired size and shape. A contact thus prepared has all the essential properties of pure mercury for the purpose for I which it .is intended and at thesame time is in a solid form, in which it can be practically used.

I do not desire to limit my invention to a copper amalgam, since other amalgams c011- structed in substantially the same manner would answer .the same purpose-such, for example, as gold, silver, cadmium, &c.; but copper being less expensive it will probably be usually employed.

Just what the actionof the amalgam is by virtue of which it obviates the welding or looking together of the contact-tips is not absolutely certain; but it seems possible that the action is similar to that of tapping with the feet upon moist sand, which brings the moisture to the surface-that is to say, the passage of static discharges may instantly bring more or less free mercury to the surface, which acts to prevent the interlocking of the devices. Whatever may be the true theory of the operation, it has been practically demonstrated that the result is as hereinbefore stated.

Referring to the drawings, Figure 1 is a side elevation, partially in section, of a .portion of a relay provided with my improvement; and Fig. 2 is a section of a mold in which the contact piece or plug is formed.

Referring to the drawings in detail, 1 is a portion of the frame of the device, which supportsa binding-post 2, with which is electrically connected the upper contact The lower contact 4 is supported bythe end of a spring 5', and the two contacts are brought into engagement by means of the magnet 6, acting upon an armature 7, carried by the spring. Each of the contacts 3 and 4 consists of a main or body portion 8 of any desired material having a cavity or recess in which is seated the amalgam contact point or plug 9. This plug has arounded end projecting somewhat beyond the extremity of its support or holder.

-In the prohess of manufacturing the contact plugs or tips 9, the support or holder Sis first placed in the cavity of the mold 10, and a sufiicient quantity of electrolytically formed amalgam paste for the size of plug or tip desired is placed inside this support or holder and pressed into the same by means of a suitable plunger or follower closely fitting the interior of the part 8.

\Vhile I have described my invention in connection with a particular form of relay and as supported bya specific form of holder, I desire it to be understood that it is not limited to any specific form of apparatus.

I claim as my invention 1. A contact for electric circuits constructed of an amalgam, substantially as described.

2. A contact for electric circuits constructed of copper amalgam, substantially as described. I

3. The method of forming an electrical contact which consists in producing an amalgam paste and compressing said paste to form a solid plug, substantially as described.

t. A circuit making and breaking device comprising two adjacent contact points, each composed of an amalgam, substantially as described.

5. An electrical contact device comprising a base or support provided with a recess and an amalgam plug seated in said recess and projecting therefrom, substantially as described.

In testimony whereof I have hereunto subscribed my name this 30th day of March, A. D. 1895.

ALEXANDER JAY XVURTS.

\Vitnesses:

P. N. NUNN, J. WM. SMITH. 

